title: Influence of vaccination-challenge interval on the protective efficacy of bacille Calmette-Guérin against low-virulence Mycobacterium tuberculosis.
abstract: The influence of vaccination-infection interval on protection induced by bacille Calmette-Guérin (BCG) was studied in an animal model of experimental airborne tuberculosis. Guinea pigs were simultaneously skin-tested with mammalian tuberculin and intracellularin and vaccinated with BCG-Copenhagen (strain no. 1331). At weekly intervals thereafter, groups of animals were infected by the respiratory route with about five viable units of a recently isolated strain of Mycobacterium tuberculosis of low virulence. The animals were necropsied six weeks after challenge, and tubercle bacilli recovered from primary lung lesions, primary lesion-free lung lobes, and spleens were counted. Protection was defined as a significant reduction in the number of bacilli recovered from the tissues of vaccinated as compared with unvaccinated animals. The data obtained for two of the three tissues indicated that BCG-Copenhagen induced a significant level of protection against this low-virulence of M. tuberculosis.
mesh_terms: D000818:Animals; D001500:BCG Vaccine / Q000627:therapeutic use*; D005260:Female; D006168:Guinea Pigs; D008168:Lung / Q000382:microbiology / Q000473:pathology; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology; D013154:Spleen / Q000382:microbiology; D013997:Time Factors; D014376:Tuberculosis / Q000628:therapy*; D014774:Virulence
chemical_list: D001500:BCG Vaccine